=> 半径 = 12.56 /2pi = 2 m
=> 底面积 = 2^2 * pi = 12.57 m
=> 体积 = 12.57 * 1.2 / 3 = 5 m^3
=> 重 500 * 5 = 2500 kg = 2.5 t
12.5除以2除以3.14等于2
2乘2乘3.14等于12.56
12.56乘1.2除以3等于5
500乘5等于2500千克,等于2.5吨